Geology Final

Front 1

What are our five sources of energy?

Back 1

--the Sun

--Gravity

--Chemical reactions (including fossil fuels)

--Nuclear fission

--Earth’s internal heat

Front 2

anoxic water

Back 2

sea water, fresh water, or groundwater that is depleted of dissolved oxygen

Front 3

What causes fossil fuels to work as a source of energy?

Back 3

a chemical reaction: chemical bonds in fossil fuels store energy that is released when it's burned

Front 4

Fossil fuels

Back 4

carbon-rich materials formed in the geologic past from the decomposition of buried dead organisms under anoxic conditions

Front 5

Oil and gas consist of hydrocarbons of varying _________ _________

Back 5

chain length

Front 6

What are the three different forms of petroleum? What determines the form they take?

Back 6

-- gas, liquid, and solid

-- form related to the number of Carbon atoms that make up the hydrocarbon

Front 7

A known supply of oil or gas is called a ___________ ______________

Back 7

Hydrocarbon reserve

Front 8

Where do hydrocarbon reserves originate and get stored?

Back 8

Underground

Front 9

Source of fossil fuels (oil and gas)

Back 9

1) Dead photosynthetic organisms sink and get buried with sediment at the bottom of the ocean,

2) the organic material is preserved under anoxic conditions

3) Mud + organics are lithified under burial and compaction to form black shale (petroleum source rock)

6) The shale is heated as it’s buried at depth

7) Heating breaks organics down into waxy kerogen

8) Kerogen breaks down to form oil and gas as it continues to be buried and heated

Front 10

Oil window

Back 10

Temperature range in which kerogen becomes oil.

Front 11

Gas window

Back 11

Temperature range in which kerogen becomes natural gas.

Front 12

__________________ organisms live in the shallow part of oceans where they can grow and store the energy of the sun in their chemical bonds.

Back 12

Photosynthetic

Front 13

Oil shales

Back 13

Kerogen-rich source rocks that have not been in the oil window. Heating transforms the kerogen into liquid hydrocarbon (shale oil) that is different from petroleum.

Front 14

Kerogen

Back 14

fossilized waxy molecules that are formed from heating the organic materials in shale. yields petroleum products on distillation

Front 15

Specifically which two photosynthetic organisms eventually form oil and gas?

Back 15

Phytoplankton and algae

Front 16

The largest oil reserves formed during the late _________, causing __________ supergrowth

Back 16

Mesozoic; phytoplankton

Front 17

How do we access tar sands?

Back 17

Mining

Front 18

Tar sands

Back 18

deposits of residual petroleum in loose sand or partially-consolidated sandstone. Contains mixture of sand, clay, and water, saturated with tar

Front 19

tar

Back 19

a dense and extremely viscous form of petroleum

Front 20

About how much tar sand is required to produce one barrel of oil?

Back 20

about two tons

Front 21

How are tar sands processed?

Back 21

After mining, they are transported to an extraction plant, where a hot water process separates the tar from sand, water, and minerals

Front 22

What formation contains the largest oil shale deposit in the world? From where does its organic matter come?

Back 22

The Green River Formation; blue-green algae

Front 23

Natural gas

Back 23

short chain hydrocarbons (C1 – C4) which float on top of oil in a reservoir. More abundant than oil and a “cleaner” fuel, but requires expensive high-pressure (dangerous) pipelines

Front 24

Four types of natural gas

Back 24

1) Methane,

2) ethane,

3) propane,

4) butane

Front 25

Hydraulic fracturing

Back 25

after a well is drilled, a high pressure mixture of water, chemicals, sand is used to blast fractures & hold them open so gas can escape up the well

Front 26

The Marcellus Shale

Back 26

a "juicy" (presence of abundant fluids) sedimentary rock formation deposited over 350 million years ago in a shallowinland sea. Contains large quantities of natural gas. located on what is now considered the eastern United States.

Front 27

Coal

Back 27

Black, carbonaceous sedimentary rock formed from the remains of organic matter in vegetation, mostly during the carboniferous. Only found in rocks younger than 350 Ma.

Front 28

Coal formation process

Back 28

1) trees in wetlands and swamps grow and store energy harvested from the sun in their chemical bonds

2) Dead plants accumulate in shallow anoxic water

3) anoxic conditions prevent decomposition (preserving the energy stored in the chemical bonds).

4) Sea-level rises and falls and buries wetland deposits under sediments

5) compaction and decay turn plant debris into peat

6) peat is buried in a basin

7) Compaction during burial squeezes out water.

8) the heat at depth alters the plant material--- most Hydrogen, Nitrogen, and Sulfur content is expelled as gases, and Carbon content increases.

9) At 70% carbon, this solid material becomes coal.

Front 29

Peat

Back 29

compacted and partially decayed vegetation accumulating beneath a swamp

Front 30

Upon what is coal rank/classification based?

Back 30

Carbon content

Front 31

Carbon content of peat

Back 31

50%

Front 32

Carbon content of lignite

Back 32

70%

Front 33

Carbon conten of bituminous

Back 33

85%

Front 34

Carbon content of anthracite

Back 34

95%

Front 35

Carbon content of graphite

Back 35

100%

Front 36

Coal mining type depends upon the depth of the _____ ______. Within 100m, coal is ______ mined. At greater depth, _____________ mining is required.

Back 36

coal seam; strip; underground

Front 37

What caused Centralia, PA to become an abandoned town?

Back 37

An underground coal mine fire

Front 38

What makes a good oil reserve?

Back 38

Being able to easily extract oil from rock using conventional methods of extraction.

Front 39

Creation of an oil reserve depends on what four factors?

Back 39

1) A source rock – where the oil is made

2) A migration pathway – where the oil moves in the subsurface

3) A reservoir rock – where the oil is stored underground

4. A trap or seal (cap rock) – what traps the oil below ground

Front 40

Source rock

Back 40

a rock containing the organic matter from which hydrocarbons eventually form; typically a black shale.

Front 41

Migration pathway

Back 41

the route that oil and gas take as they move from a source rock to a reservoir rock. Oil migrates away from the source rock as it’s squeezed out.

Front 42

How are oil and gas able to migrate through porous and permeable rocks in the subsurface?

Back 42

they are less dense than water

Front 43

Reservoir rock

Back 43

a rock with high porosity and high permeability that can contain abundant, easily accessible oil and/or natural gas

Front 44

What two rocks are known for making great reservoir rocks?

Back 44

Sandstone and limestone

Front 45

Trap

Back 45

a subsurface arrangement of impermeable cap rocks and structures that keep oil and gas underground

Front 46

Three types of traps

Back 46

stratigraphic, anticlinal, and fault traps

Front 47

Stratigraphic trap

Back 47

a trap created by depositional features where the reservoir rock “pinches out” between two impermeable rocks. Oil/gas gets trapped at the pinch. Unconformities form excellent stratigraphic traps

Front 48

Anticline trap

Back 48

oil and gas trapped by an arch feature of permeable rock underneath an impermeable rock

Front 49

Fault traps

Back 49

displacement from faulting creates contact between rocks with different permeability and, oil and gas get trapped between impermeable rocks

Front 50

Most coal contains what iron sulfide mineral that reacts with water and oxygen to form sulfuric acid?

Back 50

pyrite

Front 51

Four major energy resources found within rocks and sediment

Back 51

oil, natural gas, coal, uranium

Front 52

Geologic cross section

Back 52

an interpretation of what’s below the surface based on evidence (rock type, contacts) observed at the surface, made by using available mappable features found on the surface or interpreted from data about the subsurface

Front 53

2 rules of stratigraphic sequence (abc abc order)

Back 53

1) Folding results in repetition of rock layers that are repeated ‘in-sequence’ across the core of the fold

2) Faulting displaces rock layers, making them ‘out-of-sequence’.

Front 54

How does faulting affect stratigraphic sequence?

Back 54

omits or repeats units – making them out of stratigraphic sequence (order) at the earth’s surface

Front 55

How does folding impact stratigraphic sequence?

Back 55

produces repetition of sedimentary rock layers on either side of the fold andlimbs which commonly dip or tilt away from each other

Front 56

To form an oil reserve, oil must migrate from a ______ rock into a _________ rock

Back 56

source; reservoir

Front 57

tar sand, gas shale, and oil shale, are called ____-__________ reservoirs

Back 57

non-conventional

Front 58

How do nuclear power plants generate energy?

Back 58

by using the heat released from the fission of uranium

Front 59

How does geothermal energy generate power?

Back 59

it uses Earth’s internal heat to transform groundwater into steam that drives turbines

Front 60

How does hydroelectric power generate power?

Back 60

by using the potential energy of water. Dams halt the flow of water, storing it at high elevation Water that is released flows through turbines to create electricity.

Associated problems: flooding and population displacement during construction, alteration of stream habitat and local ecosystems

Front 61

How does solar energy generate power?

Back 61

uses solar cells to convert sunlight to electricity

Front 62

All minerals used by industrial societies must be extracted from the ________ crust.

Back 62

Upper

Front 63

Strip mining

Back 63

the practice of mining a seam of mineral, by first removing a long strip of overlying soil and rock (the overburden).

Hazard: acid mine drainage.

Front 64

Primary recovery

Back 64

Uses reservoir pressure and pumping to extract oil. Inefficient; only able to recover about 30% of the oil.

Front 65

Secondary recovery

Back 65

Fluids (steam, CO2 ) are injected to heat and push the oil upward.

Hydraulic fracturing – Artificially increases permeability.

Front 66

Metals come from....

Back 66

ore

Front 67

Mountaintop removal mining

Back 67

Tops of mountains are blasted off to expose coal seams;valleys filled with rock. Landscape is leveled; environment is permanently altered

Front 68

Acid Mine Drainage

Back 68

(associated w/ coal mining) When pyrite is exposed to the atmosphere, it weathers to release acid, iron, and heavy metals. Kills fish and other aquatic organisms

Front 69

Nuclear fission

Back 69

Enormous amounts of energy are released from splitting atoms into smaller pieces

Front 70

How do nuclear power plants generate electricity?

Back 70

Heat released from fission is used to create high pressure steam in the reactor. Steam spins turbines in a generator to create electricity.

Front 71

How do we access uranium?

Back 71

Uranium leaches out of rocks, is carried by water, and precipitates as a uranium oxide mineral in veins and fractures

Front 72

238-U

Back 72

99.3% of Uranium is of isotope 238. This isotope is not fissionable (useless!)

Front 73

235-U

Back 73

0.7% of uranium is of isotope 235. this isotope is fissionable (electricity, bombs)

Front 74

Nuclear power typically uses __________

Back 74

uranium

Front 75

Why is nuclear waste (radioactive nuclear waste rock from uranium mining) difficult to store?

Back 75

The fission process generates highly radioactive wastes that remain radioactive for thousands of years

Front 76

Biofuel

Back 76

Using plant and animal matter as an energy source. Produces CO2, but also pulls CO2 from atmosphere (net zero)

Front 77

Ethanol

Back 77

the most commonly used biofuel today - derived from corn, sugar cane, cellulose, algae, etc. Added to gasoline as a motor vehicle fuel

Front 78

_____________ panels are used to convert light to electricity

Back 78

Photovoltaic

Front 79

Ore deposit

Back 79

rock or sediment with high enough concentration of a valuable mineral that it is economically worth extracting

Front 80

Ore deposits form when....

Back 80

valuable elements and minerals-- which normally exist in very small amounts in normal rocks and seawater-- are leached from one rock, moved to another location (usually in a fluid), then re-precipitated in a concentrated mineral form

Front 81

Three steps of ore formation

Back 81

1) Source rock from which the element is originally derived

2) Transport

3) Trapping (required to concentrate the metal)

Front 82

Magmatic ore deposits form when...

Back 82

ore minerals settle to the floor of a magma chamber

Front 83

Pyrite

Back 83

iron ore

Front 84

Galena

Back 84

lead ore

Front 85

Rare Earth Elements (REEs)

Back 85

Very large, heavy elements that are often found together in geologic deposits. Heavily used for technology, especially cell phones and computers. High demand

Front 86

Why do REEs remain in the melt after other minerals have crystallized?

Back 86

they are too large to fit in common minerals that formed earlier. they go into forming unusual often valuable minerals (beryl, monazite, topaz, molybdenite, etc.)

Front 87

Hydrothermal deposits

Back 87

Ore minerals precipitate from hot groundwater solutions near magma sources and dissolve metals from rocks. Water transports metals to cooler regions where they precipitate in fractures to form veins. Also found on the ocean floor at the mid-ocean ridge.

Front 88

Secondary-enrichment ore deposits

Back 88

Groundwater dissolves an existing ore mineral (typically made of a metal and sulfur) and replaces the sulfur with oxygen or carbonate to form a new (secondary) mineral in a new location.

Front 89

What type of minerals are Malachite and Azurite?

Back 89

copper carbonate minerals

Front 90

Mississippi Valley Type (MVT) ores

Back 90

Form when hot groundwater gets squeezed out of a mountain belt and deposits minerals upon reaching the cooler surface.

Front 91

Sedimentary ore deposits settle out of....

Back 91

water

Front 92

Banded Iron Formations (BIFs)

Back 92

Sedimentary ore deposits that were deposited when bacteria began to produce oxygen gas ~2.4 billions years ago, while the oceans were full of dissolved iron that combined with the new oxygen to create rich iron-oxide deposits

Front 93

Residual ore deposits

Back 93

Extreme chemical weathering in tropical environments leaches most minerals out of the soil, except aluminum oxides and iron oxides

Front 94

Almost all Aluminum comes from _______, the rock material left behind when granite weathers. This is an example of a ________ ore deposit.

Back 94

bauxite; residual

Front 95

Placer Deposits

Back 95

Heavy minerals settle out of flowing water and concentrate along a stream bed; Important for gold, tin, and iron; Can be re-lithified

Front 96

Dimension stone, crushed stone, clay, sand, and many other materials are all examples of ______________

Back 96

Nonmetallic resources

Front 97

Where are ore deposits formed?

Back 97

1) Where igneous/magmatic and hydrothermal activity occur (plate boundaries, rifts, hot spots)

2) Where tectonic effects are overprinted by the hydrologic cycle(water transports elements away from the source)

Front 98

Are mineral resources renewable or non-renewable?

Back 98

Non-renewable

Front 99

Weather

Back 99

the short-term variation in temperature, humidity, atmospheric pressure, wind, etc. in a given region.

Front 100

Climate

Back 100

a measure of the average of weather variables over longer periods of time

Front 101

Mountain (alpine) glaciers

Back 101

Glaciers that exist in higher altitude regions at the top of mountains and fill cirques and valleys. travel downslope

Front 102

Why do continental glaciers flow?

Back 102

because of pressure applied by the weight of ice at their source areas

Front 103

Glacial horn

Back 103

a pointed mountain peak; formed by three or more cirques surrounding the peak

Front 104

Cirque

Back 104

bowl-shaped basin high on a mountain

Front 105

Arete

Back 105

“knife-edge” ridge; formed by 2 cirques

Front 106

Fjords

Back 106

drowned glacial valleys

Front 107

U-shaped valleys are formed by _________, while V-Shaped valleys are formed by

Back 107

Glaciers; rivers

Front 108

Dropstones

Back 108

sediments moved off continents by icebergs that drop into ocean mud

Front 109

Glacial till

Back 109

unsorted, unconsolided debris transported by glaciers

Front 110

Glacial erratics

Back 110

large boulders dropped by ice;don’t match surrounding bedrock

Front 111

Glaciers deposit eroded material __________ from where it’s eroded

Back 111

downhill

Front 112

Moraines

Back 112

unsorted glacial debris piles

Front 113

Lateral Moraine

Back 113

moraines accumulate along the side of a valley glacier

Front 114

Medial moraine – mid-ice moraine

Back 114

mid-ice moraines that form in the middle of a glacier

Front 115

Terminal/end moraine

Back 115

moraines that form along the front edge (snout) of the glacier

Front 116

What do moraines tell us about the geologic past?

Back 116

how far glaciers traveled during ice ages

Front 117

Where do continental glaciers (ice sheets) form?

Back 117

They spread over substantial areas of the continents. Found at the higher latitudes, near the poles.

Front 118

Why do sea level falls during an ice age?

Back 118

because the water is stored in ice on land-- deglaciation returns water to the oceans and floods the coasts.

Front 119

Why is the North American continent slowly rising?

Back 119

The weight of the ice sheets during the ice age pushed the continent down into the mantle. A huge weight was lifted off the land when the ice melted.

Front 120

temperate glaciers

Back 120

melt during at least part of the year

Front 121

Polar glaciers

Back 121

Remain frozen throughout the year

Front 122

Zone of ablation

Back 122

area of net ice loss (melting, calving, etc)

Front 123

Zone of accumulation

Back 123

glacial buildup of snow under cold temperatures and precipitation

Front 124

Advance or retreat is determined by difference between_______________ and _______.

Back 124

accumulation and loss

Front 125

Glacier toe (terminus)

Back 125

the end of a glacier

Front 126

Albedo

Back 126

The ability of Earth to reflect light

Front 127

What 3 things are required to warm the earth?

Back 127

1. A source of heat (solar radiation)

2. Something that will trap heat near the surface of the Earth (Greenhouse gases)

3. Something that will distribute this heat throughout the planet (Wind and Ocean currents)

Front 128

Snow and ice reflect large amounts of incoming ______ energy

Back 128

Solar

Front 129

Warming creates a positive __________ _____ for albedo

Back 129

feedback loop (warmer temperatures --> melting of snow and ice ---> decreased albedo (more solar radiation absorbed) ---> warmer temperatures.....)

Front 130

10,000-100,000 year climate cycles are called __________ cycles, and are driven by small changes in Earth’s orbit(eccentricity, tilt, and precession) called _______ __________

Back 130

Milanković; “orbital forcing”

Front 131

Orbital eccentricity

Back 131

the degree to which Earth’s orbit is circular or elliptical – impacts seasonality of solar insolation

Front 132

Solar insolation

Back 132

the amount of solar radiation hitting the surface of the earth. Basically that means how much sunlight is shining down on us

Front 133

Do high northern latitudes receive more or less solar radiation when tilt is small?

Back 133

less

Front 134

Precession

Back 134

changes in the orientation of the spin axis with respect to the earth’s orbit

Front 135

During glacial periods, continental ice moves towards ___-latitudes. During interglacial periods, permanent ice exists only at the ____.

Back 135

low; poles

Front 136

Milankovich cycles only impact the________ and________ of insolation, not the total amount of energy hitting the earth.

Back 136

seasonality; location

Front 137

The Permo-Triassic Hothouse

Back 137

A massive volcanic eruption in Serbia whcih continued for hundreds of years, igniting coal deposits and released CO2. Formed Large Igneous Provinces. Release of sulfur gases acidified the oceans and killed marine life. Event led to the End Permian Mass Extinction

Front 138

How does mountain building lead to overall climatic cooling?

Back 138

process consumes CO2 in rock weathering

Front 139

Pliocene Ice Age

Back 139

Past 1-2 million years has seen dramatic climate variation, with five major glaciations and 20-30 minor glaciations separated by interglacial periods

Front 140

Carbon Cycle

Back 140

The cycle through which carbon passes back and forth among the biosphere, atmosphere, hydrosphere, and lithosphere.

Front 141

How do tectonics regulate global temperature over long time scales?

Back 141

through the following steps:

1)volcanoes release CO2 to the atmosphere;

2) CO2 reacts with rain water to form carbonic acid;

3) carbonic acid reacts with silicate rocks during weathering to release bicarbonate ions into surface water;

4) bicarbonate ions are transported to the oceans where they combine with calcium ions to form calcium carbonate minerals that are deposited on theocean floor;

5) calcium carbonate minerals are eventually subducted back into the mantle, and carbon dioxide gas is released from the rocks during melting and rises up through volcanoes back to the atmosphere.

Front 142

The Terrestrial Carbon Cycle

Back 142

Fast carbon cycling between soil,biomass, and the atmosphere

Front 143

Respiration

Back 143

Animals and other organisms (bacteria,fungi) use O2 to break down biomass and release CO2 back to the atmosphere

Front 144

Atmospheric carbon concentrations pulse(ebbs and flows) on a ______ cycle

Back 144

yearly

Front 145

Long-term carbon cycle

Back 145

Silicate rocks react with atmospheric CO2 during weathering . Volcanoes release CO2 as carbonate rocks are subducted.

Front 146

Tools for documenting global climate change include...

Back 146

-- the stratigraphic record

--paleontology

--oxygen–isotope ratios

-- bubbles in ice

-- growth rings in trees

-- human history

Front 147

What term refers to how geology regulates climate over long timescales and includes volcanic degassing, rock weathering, carbonate formation in oceans, and subduction?

Back 147

the "global weathering thermostat"

Front 148

Snowball Earth

Back 148

an icehouse period that resulted from extreme chemical weathering following the formation of the supercontinent Rodinia. A positive feedback between cooling and increased albedo caused the entire Earth to be covered in snow and ice.

Front 149

____________ __________ ___________ deposited in the Snowball Earth period indicate that the oceans were cut off from the atmosphere during this time

Back 149

Banded Iron Formations

Front 150

Gradual global cooling during the ________ has resulted from increased rock weathering following the uplift of the Himalayas

Back 150

Cenozoic

Front 151

Today, ______ provides over 80% of the world’s energy.

Back 151

fossil fuel

Front 152

The Keeling Curve

Back 152

Atmospheric CO2 measurements at Moana Loa Observatory since 1958

Front 153

What condition must be met to produce oil from kerogen?

Back 153

the temperature must fall in the window between the 90° and 150°C.

Front 154

Oil and natural gas rise into oil traps because…

Back 154

hydrocarbons are less dense than water, so they are relatively buoyant and float above groundwater

Front 155

As the rank of coal increases, the proportion of carbon in it ________ .

Back 155

Increases

Front 156

The basic reaction that takes place in a nuclear power plant is ________ . If the fuel rods get too hot, they can cause a _________ .

Back 156

Fissioj; meltdown

Front 157

Why isn’t a typical outcrop of granite considered an ore deposit?

Back 157

It does not contain a high enough concentration of valuable metals

Front 158

A common way to mine placer ores is to …

Back 158

pan the sediments at the bottom of a stream.

Front 159

What process occurs during glacial retreat?

Back 159

The position of the glacier's toe (end point) moves back toward the origin of the glacier, even though ice continues to flow toward the toe

Front 160

How can you tell the direction that ice flowed in a region that was covered by ice during the last ice age?

Back 160

Flow direction is parallel to the direction of glacial striations.

Front 161

CO2 gas dissolves in rain water to form _________ acid, which attacks ________ minerals in rocks and releases various ions into water

Back 161

Carbonic; silicate

Front 162

Bicarbonate ions combine with ________ ions to form ________ _________ minerals, which are deposited on the ocean floor to form limestone

Back 162

calcium; calcium carbonate

Front 163

What do tree rings tell us about paleoclimate?

Back 163

Trees grow more in warm/wet years and less in cold/dry years.

Front 164

What can the study of fossil pollen in sediments tell us about climate change?

Back 164

shifts the occurrence of cold-adapted and warmth-adapted plant species at different latitudes

Front 165

18-O/16-O in ice cores reveal the temperature in which snow formed. Higher 18-O/16-O ratio indicates a _____ climate. Lower 18-O/16-O ration inidicates a _______ climate

Back 165

warmer; colder

Front 166

In a very cold climate,what is the behavior of oxygen isotope ratios in plankton fossils?

Back 166

the ratio of 18-O to 16-O is high because most of the 16-O is trapped in ice on the continents

Front 167

The record of CO2 concentration in the atmosphere shows that the concentration of this gas has steadily _______________ since the mid-19th century

Back 167

increased

Front 168

What is the main control on global climate over geologic timescales?

Back 168

Fluctuations in solar output

Front 169

Is nitrogen a GHG?

Back 169

no

Front 170

What is the term that has been proposed to describe Earth’s most recent epoch?

Back 170

Anthropocene